Treatment of oil shale



Oct. 2 1923.

R. c.. IJLJNDAS` ET Al.

TREATMENZIT 01?l OIL SHALE Filed De'c. 23 1921 ROY -DUNDAS, F LOS ANGELES, AND RAYMOND T. HOWES, 0F SANTA MARIA, CALI- FORNIA, SSIGNORS TO S. E. COMPANY, A CORPORATION OF DEL'AWARE.

n TREATMENT or oir. sHA'LE.

application niet December as, i921. serial ivo. 524,515.

l To aZZ- whom t may concern:

Be it known that we, ROY C. DUNDAS and RAYMOND T. HoWEs, citizens of the United States, and residents, respectively, of Los Angeles, California, and Santa Maria,fCali fornia, have invented a certain new and useful Treatment of Oil Shale, of which the following is a specification.

This invention relates t`o the distillation of oilshales, by which term we include all natural minerals'which contain hydrocarbons and' yield oils when subjected to heat,

` either by destructive distillation or by simple distillation.

The invention consists in using the shale itself, that is, combustible constituents of the shale, as the fuel to, support the internal .combustion and furnish the heat which distils off the oils. A zone of combustion is established in a charge of shale, traveling slowly downward, with the products of combustion heating underlying layers and oarrying forward and away the vapors Aas they are formed. To maintain this zone of combustionand develop heat in the underlyin distillation zones, or what may be calle working zones, we supply a current of air in regulated amount and at a regulated rate, and we may control the temperature and rate of combustion by suitably modifying the current so supplied, as by using humidiied air, or admixing or simultaneously introducing gas, steam, superheated steam, or

Vany other medium capable of producing the desired result. The use of steam is particularly advantageous when the shale is rich in nitrogenous matter, as it assists in the formation of valuable by-products, such as ammonium compounds. .In addition to the above, an essential feature of our process consists in so conducting it that' the zone of combustion will progreively travel downward from the top to the bottom of the chamber containing the shale, driving oil' the oils from the shale below it as it advances downward and the oils being largely condensed by their passage through the column of relatively cool shale and in doing so, transmitting some of their heat to said shale, so that, as the zone of combustion approach a layer of shale, the latter is gradually heated and finally freed from oil, thereby becoming a suitable fuel to maintain the combustion in the descending zone of combustion.

ed to an air supply pipe 5. 3 is another 4inlet pipe for steam or gas. The chamber may be covered Awith insulation 6 and lined ff with fire-bricks 6. a' grate 1, which can b e dumped, and is closed at the bottom by a door 7, which is removable to discharge the spent shale. 8 is the 'outlet pipe for the oils, connected to a IThe chamber contains receptacle 11 and provided with a valve 9 and a" gage 10. 12 is a pipe for drawing off uncondeiised vapors, leading to a condenser 13, from which the condensates are led through pipe 15 to a suitable container 16. 14: is the suction pump'.

'.lhe voperation is as follows: The chamber 1 is filled with shale and the top layer is ignited in any convenient way. The cover 1s then applied making an air-tight'ti" The suction pump 14V is started andthe valve 4 is opened to admit the desired amount of air, and if desired, also inert .gas or steam through pipe 3. In a very short time, a zone of internal combustion forms near thev top of the column of shale, and communicates its heat to the unignited shale below driving oiits oil-content, which is carried downwardly through the column of relatively cool shale. With the proper admixture and rate of supply of the air, a layer of the shale will burn with a substantially constant temperature and evolution of heat, and the zone downward throughthe relatively cool shale,

being prevented by the current of air from passing upward into the zone of combustion,

so that, once they are formed, the are not subjected to any secondary distil ation or cracking Some of the products are condensed in the cooler shale, while others are drawn 0E into the condenser 13. As the zone of combustion approaches the bottom peratureis maintained during the. progres. S0

ample, all or nearly of the chamber, a progressively smaller quantity of the products is condensed in the chamber and more in the condenser. Dun ing the process of combustion of the shale in the zone of combustion, its heat 1s ,communicated to the zone immediately below it. its the temperature of said lower zone reaches the critical point, say from 600 F. to 800 lF., the -oil formed is immediately drawn away from. the zone of combustion and passes into and through the lower and successively cooler zones beneath. As the ,temperature in a zone rlses to 800, vitor exall of the oil has been formed and expelled 'from said zone, leaving behind a residual carbon which constitutes the fuel for the progressive combustion.

This combustion weconfine to the carbonized zone by supplying only suicient a1r or oxygen to unite with the carbon. We believe that, above the temperatures Amentioned above, no further 'combination takes place tovproduce hydrocarbon o1ls.unless they be uncondensable gases, in which case such' -gases are consumed in the zone of .combustionand assist in maintaining its high temperature, which the pyrometer shows to be about 1910 F. lhis. high degree of tem-l sion of the combustion from the top tothe bottom of the chamber,while -that of the 'distillation zone, immediately below the zone .i

of combustion, remains constant at from 600 to 800A F. The downward advance of the zone of combustion we found to be about one foot per. hour, but this rate may be variedto suit conditions.

iI'lavin'g thus ldescribed our invention,

.. whatwe claim is'- f.

1. The method of distilling vo'l shale, or the like, which'consists in confining. a body of shale in a closed chamber, igniting the top f stratum'of said body, causing a current of air to pass downwardly through said body in just suiicient quantity to maintain combastion in a zone of the shale and to cause said zone to travel slowly 4downward through-the body of shale, and recovering the products, driven .of bythe heat otcombustion from saidzone, at the bottom of the chamber.

'a rh@ mataba of aisaning. on sha1@ or,

` through incense the like, which consists in confining a charge of shale in a closed chamber, igniting the top stratum of said. charge.J causing air t0 pass downwardly through said charge, whereby a zone of internal combustion is created and caused 'to slowly move downward through the charge, introducting gas with the air to modify its oxidizing action, collecting the condensed oils from the bottom of the chamber and condensing the gaseous products drawn' oli' from the same.

3, rl`he method of distilling a charge of oil shale, or the like contained in a ,closed chamber, which consists in setting up a zone of direct internal combustion in the, shale itself at the top of said chamber, lsupplying a downward current of air in such amount and at such -a rate' as to maintain combustion in said zone, suitably modifying the air of said current to prevent unduly'energetic combustion and development of. heat, causing sald zone to progressively travel downwardly the charge and' recovering the condense and nncondensied distillatlon products at the bottom ofthe chamber.

4c. 'llhe method of treating a charge of oil shale to recover volatilizable product/s therecharge in a vertical closed chamber, initiating a' zone of combustion in the shale itself at the top of the charge, passing a current of air downwardly through the chamber, mixing a modifying` agent with said air to control the temperature and rate of combustion, wherebys'aid zone is caused ,to .travel slowly downward through the chamber, and drawing ed and recovering the products from the bottom of the chamber.

5."llhe method of distilling oil shale or 4the like, which consists in slowly and progressively burning a charge of shale in a closed chamber from the top downwardly, malntaming the combustion at a substantially constant temperature by supplying fand regulating a downward current of air through the chamber, and drawing od the ,hydrocarbon products at the bottom of the chamber. Y

In testimony whereof we have set our hands.

RY @..DUNDAS RAYMOND T. H095. 

